Evidence exists that the activation of actions activates the same cortical motor areas that are involved in the performance of the observed actions. The neural substrate for this phenomena is the mirror neuron system. It is generally assumed that mirror neurons have a basic role in understanding the intentions of others and in imitation learning. There is evidence that action observation has a positive effect on rehabilitation of motor disorders after stroke. The aim of this study is to demonstrate that action observation followed by the repetition of the actions previously observed has a positive impact on rehabilitation of the upper limb in children affected by hemiplegia as a consequence of Cerebral Palsy. In particular, the purpose is to assess if mirror neurons could improve the amount, the quality and the velocity of movements and the cooperation between the two upper extremities.